Rock drill



Feb. 23, 1932.

W. A. SMITH, JR

ROCK DRILL Filed Dec. 8, 1928 INVENTO'R. I/Filha AJmifla Sr.

HIS ATTORNEY NI E STATES Patented Feb- 1932'.

WILLIAM A. smrmlsn or na ro PENNSYLVANIA, Ass eNon roiNeERsoLn-nANn ooraNY, orennsny crry, new JERSEY, A coaroaa'rronor new JERSEY ROCK DRILLApplication .filed December 8, 1928.. fieri al No; 324,726;

This invention relates to fluid actuated tools, but more particularlytoa fluid actu-' ated rock drill in which the hammer piston reciprocatesindependentlyof the Working implement which it is adapted to actuate.

One object of the invention is to assure thorough lubrication of thecooperating sur-. faces of the chuck mechanism and the element. wherebyit is guided such as thefront head of the rock drill. V

.Another object is to-enable lubricant to be supplied tothesurfaces in arock drill in which the interior of the chuck mechanism is vented to theatmosphere so thatthe lubricant will have to be conveyed forwardly ofthe vented portion of the chuck mecha- Other objects will be in partobvious and in part pointed outhereinafter. f V, In the drawingsillustrating one form which the invention may assume in practice and inwhich similar reference characters refer to similar parts, 1

Figure 1 isalongitudinal sectional elevation of a rock drill constructedin accordance with the practice of the invention, 7 Figure 2 is atransverse view taken through Figure 1 on the line 2-2 looking in thedirection indicated by the arrows, and.

Figure 3 is a similar-view taken through Figure 1 on the line33 lookingin the direc-v tion indicated by the arrows.

Referring more particular y to the drawings, A designates acylinderhaving a pis-. ton chamber B in whlch 1s disposed a rec 1procatoryhammer'piston C. The cylinder A; has a free exhaust port A5 which iscontrolled by the piston C. A back head D is disposed on the back end ofthe cylinder A and on' the front-endof the cylinderisa front head E. Thecylinder A, the front head E and the back head' D form the casing of thedrill and are held operative relationship by side bolts F, disposed onopposite sides of the drill.

-At the rearward end of the piston chain ber B is an enlarged bore Gforthereception] of a valve box generally designatedaby Hand comprisingin this instance a pair of plates J and K. The valye boxi H forms aclosure for the rearward end of the piston chamber B and the plate J issuitably recessed to form avalve chamber .L inwhich is disposed 'adistributingvalve O of the os-' ,cillatory plate type.

In the plate K are formed inlet passa es P and Q, which arecontrolledby'the va ve O. The inlet passage P opens directly into therearward endof the piston chamber B and the inlet. passage Q, which is afront inlet passage extends through both the plate K and through thecylinder A tothe front end of the piston chamber B wherewith it.

communicates through a port R. I

T he plates J and K are provided with bores S and T respectivelyfor thereception ofv a rifle bar U.. a The contiguous portions of the boresSandT maybe enlarged to receive a bushing V whichencircles the rifle'barU at this point and also extends through an aperture W in the valve 0.The bushing Y; thus serves to prevent leakage of pressure fluid from thevalve chamber L along the rifle bar into the rearward end of the pistonchamber B.

. In the construction showmthe plate J acts as a seat for a ratchet ringX which is disposed in the rearward end of the bore G and encircles ahead Y of the rifle bar-U and which head carries spring pressed pawls Zadapted to cooperate with the ratchet ring X in a well known manner forimparting rotary movement to the piston.

Thervalve box H, the ratchet ring X and the rifle bar-Ulare held in thebore G by the back headD and to this-end the back head D is providedwith a flange 6 which seats on the ratchet ring --X and. forms'one sideof-a' supply reservoir 0 in the back head D.

Pressurefiuid for actuating the piston C the back head through aconnection (not shown) but the point at which it'may-be attached to theback head D is indicated by a throttlevalve chamber dinwhich is disposeda throttle valve 6. g p a central bore f into which the pressure fluidmaybeintroduced and has a port j in one side which, when the throttlevalve 6 is-in its'lopen position; will "register with a passage 7: 10

may be conveyed from a source of supply to 1 The throttlevalve "e' has.

in the back head D and openinginto the supply reservoir 0.

In the ratchet ring X and the plate J are supply passages 0 which aflordcommunication between the supply reservoir 0 and the valve chamber L. Inthe present instance however, a supply chamber p is formed in the plateJ adjacent the valve L and the supplypassages 0 open into the saidsupply chamber pfor constantlysupplying pressure fluid thereto. a

The piston C is of the differential type and as shown has a flutedforward extension g" which is guided slidably by a bore 7' in a front;

cylinder washer s which acts as a closure for the front end-of thepiston chamber B. The

front cylinder washer s has an annular sleeve or extension at the-frontend of which is a lateral flange M which lies between the adjacent endsof the cylinder Av and the front head E and between which element saidflange W is clamped to hold the front cylinder washer s securely inposition. The interior surface 4) of the extension t acts as a guidingsurface for one end of the chuck 'w. The chuck also extends into a boreas in the front head'E whereby it is guided at its forward end. In therearward end of the chuck w is threaded a chuck nut 3 which may besuitably fluted to interlock slidably with the fluted extension 9 of thepiston C.

The forward end of the chuck 'w is provided with clutch members 2adapted to lock with similar-clutch members 2 of a chuckdriver3-disposed in the frontend of the bore 00'. The chuck driver 3 maybe provided with the usual ribs 4 tointerlock with wings 5 carried by aworking implement 6 which extends into cavity 7 in the chuck w toreceive the blows of I the hammer piston O- The rearward end or shank 8of the working implement 6 extends into 'and is guided by a chuckbushing 9 fitted into the forward end of'the chuck w. In orderto preventthe passage of any pressure fluid which may leakpast the pistonextension into the working implement and thence through the workingimplement into the drill hole which, as is well known, is objectionablein certain localities where, because of the peculiar nature of the rockbeing drilled, the dust resulting from drilling when inhaled has beenfound to be injurious to the health of the operators; the front cylinderwashers is provided with an internal annular recess 10 which encirclesthe fluted portion of may. leak past the pistonextension Q will be thepiston O and communicates with the atmosphere through a port 11 in thefront cylinderfwas her and the cylinder'A. Due to this arrangement anypressure fluid which intercepted by the recess '10 and will then beexhausted to the atmosphere 7 Similarly the chuck cavity 7 is'vented tothe atmosphere through'a port 12 leading from the chuck cavity to theatmosphere to provide an avenue of escape for any pressure fluid whichmay flow from the rearward end of the piston chamber B through thepiston and into the chuck cavity 7.

As. is well known, in modern drilling practice it is customary toconstantly supply lubricant to the various surfaces of the relative- 1ymovable parts of arock drill by conveying the lubricant thereto throughthe medium'of the pressure fluid utilized for actuating the drill.Lubricant may be introduced into the pressure fluid in various manners.One method which has met with considerable favor is to dispose an airline oiler in the pressure fluid supply line and introduce the lubricantinto the main pressure stream in suitable form andquantitiesto supplythe require ments of the rock drill. Another method frequently employedfor accomplishing this purpose. is to provide the drill with meansembodied in itself to supply such lubricant as may be required for thebest operation of the drill. One of the latter devices is incorporatedin the drill illustrated and comprises a reservoir 13, for lubricantsuch as oil, formed in the periphery of the front cylinder washer s andfor which the wall of the cylinderA forms an outer bounding surface. Thelubricant may be introduced into the reservoir 13 through'a 'flllingopening '14: in the cylinder A normally sealed by a filler plug'15. 1 i

For the sake of simplicity of illustration; the lubricating system shownis intended to supply lubricant to the various portions of the rockdrill only immediately prior to the starting of eachperiod of operationof the drill. To this end the cylinder A is provided with a passage 16which communicates at its front end with the reservoir throughpassages'li in the cylinder A andthe front cylinderwasher s. The passage16 extends municates in this instance with a supply, passage 0 through aport 18 in the cylinder A. and the rotation ratchet X so that when thethrottle valve e is opened to supply pressure fluid-tothe drill pressurefluid will at the same time be admitted into the reservoir 13 to exert apressure on the oil therein.

Owing to the fact that the'reservoir l3is vremotely located from thepoint, such as'the port 18 through which pressure fluid is admitted intothe reservoir, there will be no oil conveyed from the reservoir intothemain pressure fluid stream-during thenormal operation of "the drill;However Vwhen the throttle valve 6 is closed to cutoff the supply ofpressure fluid to the valve chamber L the pressure fluid which haspreviously been entrapped in the reservoir and the passage leadingthereto will also be exhausted into the valvechamber L and will carrywith it a portion'of oilsuflicient to lubricate-the movable parts of thedrill such as the piston and the valve preparatory tothe subsequentdrilling operation. Obviously, a considerable portion of oil will thenremain in the valve chamber L and when the drill is again set inoperation, such oil will be blown from the valve chamber and will passthrough the inlet passages P and Q, to the ends of the piston chamber B.

In order to assure an adequate quantity of lubricant to the cooperatingsurfaces of the chuck mechanism such as the chuck w and the chuck jaw 3and the elements whereby they are guided as the bore w of the front headand the surface 0 of the extension t, the cylinder, the flange u and thefront head E are provided with a passage 19 which leads from the forwardextremity of the inlet passage Q, to a point near the front end of thefront head E. In the front head E are a pair of ports 20 and 21 whichbranch from the passage 19 and ,open into the bore w. Similarly in thefront portion of the cylinder A is apassage 22 which leads from thepassage 19 through the extension't to 111- bricate the surface of therearward portion of the chuck w. 7

To insure a proper distribution of the oil flowing through. the inletpassage Q, between the front end of the piston chamber B and the chuckmechanism a restrictedport 23 is formed between the passage 19 and theinlet passage Q, to avoid an excess of oil to the chuck mechanism and areduction in the supply of the oil to the front endof the piston chamberB.

As explained, the connecting port 23 between the inlet passage Q, andthe passage 19 will serve to supply oil to the chuck mechanism throughthese channels only immediately prior to each drilling operation. It mayhowever be desirable that oil in suitable quantities be constantlysupplied to the chuck mechanism and in order to secure this result thefront cylinder washer s is provided with annular groove 24.

The groove 24 is preferably located slightly in advance of the forwardpassage 17 so that the pulsations occurring in the reservoir 13 willforce oil from the forward passage 17 between the cooperating surfacesof the front cylinder Washer s and the cylinder A into the groove 24from whence it will flow into the passage 19 through a connectingpassage 25. The amount of oil thus conveyed rom the reservoir into thegroove 24 may be readily controlled by the degree of clearance betweenthe front cylinder washer and the supporting surface of the piston A orby the spacing of the groove 24: and the passage 17.

The present invention has been found to be well adapted for supplyinglubricant to the chuck mechanism of rock drills, particularly in drillswhere, as in the present instance, the chuck'fc'avity andlvotherinterior portions ofthedrill are VBDtQdztOffhBfitIIlOS-phereolHeretoforeyit has been foundto bean" exceedinglyadiflicultmatterlto lubricate V the element forwardly ofv the vented portions 2 ofthei'drill. In fact the life of. these parts in drills as formerlyconstructed has invariably been short; This vwas due tov the'fact thatanylub-ricantWhich was conveyedwby' the pressure fluidfiowingpast thefluted err-* tension of; the piston was immediately fexhausted to theatmosphere withoutanyap; 3

preciableamount of it being deposited-won the relativelyfmovablesurfaces of the. chuck mechanism and the stationary :parts of the drill.:The present inventionilf'orms 'a-convenient means of providingadequ'ate 'lubri cant to'the chuck mechanismrand hasbeen foundttogreatly prolongthewlife ofzthese parts both in rock drillsfof' thevented type orthose which are unvcnted.

- The following is'a briefdescript-ion 5f the operation. of'thedevice:Afterthert-hrottle' valve 6 has been openedto set the percussiveelementof the drillin operation,rpressure fluid will-flow through the port 18,through thepassage 16 and the ports 17 into the reser voir 13tolcreatexa pressure therein'on the.

foil; Duringzthe subsequent operation ofthe drillzthe pulsationsoccurring in .the1reser-.

voir due to the admission and cutofii ofpres- I and through the passages22, 21-and 20 and will be delivered to thesurfaces-of the chuck w andthe chuck jaw 3. Due to the pressure acting against these surfaces theoil will, be

suitably distributed longitudinally of the chuck mechanism. Any pressurefluid which may leak past the rearward end of thechuck w will find itsway into the recess 10 and will then escape to the atmosphere throughthe ios port 11. V Likewisesuch pressure" fluid that r flows from theports .20 and 21 into'the bore and which may find-its wayinto-theinterior of the chuck mechanism will escape; either throughtheforwardend of the chuckjaw 3 or will flow rearwardlyinto the chuckcavity 7 from whence it will escape to the atmosphere through the port12. I

VVlienthe throttle'valve e is closedto stop the drill and the pressurefluid existing-be tween the throttle valve .andthe' valve chamher willbe exhausted therefrom the pressure fluid in the reservoir-13 will thenescape through the passage 16 and the port 18 and through the supplypassage wherew'ithit is connected into the the valve chamber-L. v

This pressure fluid will carry with it oil which will be deposited inthe valve chamber 1 9 to the cylinder, a chuck in the bore, and a andwhen the drill is again setin operation the inrushing, vpressure fluidwill blow the oil from the valve chamber through the inlet passages bothintoithe piston chamber and through the passages connecting the frontinlet passage with the chuck mechanism. 1

LI claim:

. 1. In a fluid actuated rock drill, the combination of a cylinder andafront head having a bore, a valve chamber, a distributing v I valve inthe valve chamber, means for supspecification.

plying lubricant to-the valve. chamber, a chuck in the bore, and apassage in the cylinder and the front head leading from the valvechamberfor conveying-lubricant from the valve chamber to the cooperatingsurfaces of the chuckand the; bore, said passage being controlled by thevalve.

2. In a fluid'actuated rock drill, the combination of a cylinder and afront head havv ing a bore, a valve chamber, a distributing valve in thevalvechamber, means for supplying lubricant to the valve chamber, inletpassages leading from the valve chamber to the cylinder to conveypressure fluid and en trained lubricant to the cylinder, a chuck in thebore, and a passage in the cylinder and the front head associated withone inlet passage for conveying lubricant to the cooperating surfaces-ofthe bore and the chuck. 3. In a fluid actuated rock drill, thecombination of a cylinder and a front head having a bore, a valvechamber, a distributing valve in the valve chamber, means for supplyinglubricant to the valve chamber, a front inlet passage'and a rearwardinlet passage leading from the valve chamber to the cylinder to conveypressure fluid and entrained lubricant from'the valve chamberpassage'leading from the front inlet passage to the boreto conveylubricant to the cooperating surfaces of the bore and the chuck. v

4. In a fluid actuated rock drill, thecombination of a cylinder and afront head having a bore, a chuck in the bore, a valve chamher, a valvein the chamber, means forsintroducing lubricant into the valve chamber,

and a passage leading from the valve to the bore and controlled by thevalve for intermittently conveying pressure fluid and entrainedlubricant from the valve chamber to the cooperating surfaces; of thechuck and the bore. v 1 y In testimony whereof I have signed thisWILLIAM A. SMITH, SR.-

